标签：hat wiki bit get smart ati another from leetcode
Note:
1. Very smart way of calculating how many difference from bits: https://en.wikipedia.org/wiki/Hamming_distance#Algorithm_example
2. Another way is counting how many 1s and 0s per bits. Then the contribution of that bit will bt C(1, k) * C(1, n - k).
class Solution { public int totalHammingDistance(int[] nums) { if (nums.length < 2) { return 0; } int result = 0;; for (int i = 0; i < nums.length; i++) { for (int j = i + 1; j < nums.length; j++) { result += getDistance(nums[i], nums[j]); } } return result; } private int getDistance(int a, int b) { int c = a ^ b; int result = 0; while (c != 0) { result++; c &= c - 1; } return result; } }
class Solution { public int totalHammingDistance(int[] nums) { if (nums.length < 2) { return 0; } int result = 0;; for (int i = 0; i < 32; i++) { int ones = 0; for (int j = 0; j < nums.length; j++) { ones += (nums[j] >> i) & 1; } result += ones * (nums.length - ones); } return result; } }
LeetCode 477: Total Hamming Distance
标签：hat wiki bit get smart ati another from leetcode
原文地址：http://www.cnblogs.com/shuashuashua/p/7469865.html
